Apparatus for machining and threading pipe sockets and the like



May f7, 1938.

F. WEISER APPARATUS FOR MACHINING AND THREADING PIPE SOCKETS AND THELIKE 9 Sheets-Sheet 1 Filed Aug. 22, 1936 May 17, 1938. R wElSER2,117,778

APPARATUS FOR MACHINING ANb THREADING PIPE SOCKETS AND THE LIKE FiledAug. 22, 1936 9 Sheets-Sheet 2 May 17, 1938. R F, WEI ER 2,117,778

APPARATUS FOR MACHINING ANDTHREADING PIPE SOCKETS AND fI'HE LI-KE FiledAug. 22, 1956 9 Sheets-Sheet 3 R. F. WEISER May 17, 1938.

APPARATUS FOR MACHINING AND THREADING PIPE SOCKETS AND THE LIKE Filed.Aug. 22, 1936 9 Sheets-Sheet 4 May 17, 1938. R. F. WEISER 2,117,778

APPARATUS FOR MACHINING AND THREADING PIPE SOCKETS AND THE LIKE FiledAug. 22, 1936 9 Sheets-Sheet 5 R. F. WEISER May 17, 1938.'

APPARATUS FOR MACHINING AND THREADING PIPE SOCKETS AND THE LIKE FiledAug. 22, 1936 9 Sheets-Sheet 6 .7 Wefsen y 1938. r R. F. WEISER2,117,778

APPARATUS FOR MACHINING AND THREADING PIPE SOCKETS AND THE LIKE FiledAug. 22, 1956 9 Sheets-Sheet 7 Fi ji y 1938. R. F. WEISER 2,117,778

APPARATUS FOR MACHINING AND THREADING PIPE SOCKETS AND THE LIKE FiledAug. 22, 1936. 9 Sheets-Sheet 8 7f 7'? Waisen" vve v a)" May 17, 1938. Iw sE 2,117,778

APPARATUS FOR MACHINING AND THREADING PIPE SOCKETS AND THE LIKE F iledAug. 22, 1936 r 9 Sheets-Sheet 9 H \H llll 158 1529 E 169 Ey] 168AbJSOcKET /TEND 2ND E/VD A02 SOCKET atented May 17, 1938 STATS OFHCERudolf Francis Weiser, Sketty-Swansca, South Wales Application August22, 1936, Serial NoL'WfiM Great Britain August 23, 1935 11 Claims. (Cl.-128) The invention relates to a method of and apparatus for machiningand/or threading sockets and the likefrom blanks for the production ofsuch tubular components as couplings, jointers, screwed inserted joints,tool joints or rings as used in the boring tube industry.

In particular the invention is adaptable to the production of socketsfor boring tubes having internalscrew' threads at each end whichconverge towards the middle of the socket.

of the screw threads is a very essential requirement and the moreimportant tolerances which are specified are for:

(a) The major and minordiameters of the imaginary irustum of cone formedby the thread tops. r

(b) Pitch oi thread.

(0) included thread angle.

(:1) Alignment of axes oi. the opposed irustums of cones.

Considered individually the, tolerances permitted for these variousparts may'appear generous, but with the combination of all factors it isimpossible with existing machines to work within the full tolerances onmass production lines with dimensions which correspond to a set standardof dimensions and with the obtaining of perfect alignment of the axes ofthe 0pposed frustums of cones.

Present day methods consist in chucking the blanks truly to the outsidediameter in a lathe, after which one end is'faced, bored, recessed,thread depth chamfered, and outer end chamfered, followed by a threadingoperation of several cuts by means of former tools or chasers. Machiningoperations, other than threading, are also conducted in several cuts andtool movements. Upon the completion of one end, it is 40 usual for thatend to be screwed on to a short tapered plug or mandrel on anotherlathe, whereupon the same sequence of operations is repeated for theopposite end.

Sometimes the socket blank is machined (other than threading) on a lathein two settings, after which it is passed to a tapping machine for screwthreading one end, whereupon the socket is removed and again screwed onto a short centring plug or mandrel of a second tappingmachine whichscrew threads the opposite end.

The mandrel referred to has a constant pitch diameter and when it isconsidered that it is impossible to thread sockets without some diametervariation, it will be appreciated that the mandrel must be screwed tothe smallest pitch In connection with boring tubes the accuracy diameterof the thread which is likely to occur in a batch of sockets. On theother hand, when a socket having the largest permissible pitch diameteris screwed upon the mandrel the slackness between the socket and mandrelmakes it impossible to obtain accurate axial alignment of both socketends.

The above epresent day methods necessitate chucking each end of thesocket separately at least once which renders it practically impossibleto ensure that the axes of the two socket ends coincide. Thismalalignment also affects the thread angle relatively to the true axisof two pipes'when coupled together to form a string. It is an essentialrequirement of the boring tube industry that a stringof pipes should bein perfeet alignment. It is necessary, therefore, to force pipe lengthswhich are out of alignmentdue to incorrectly threaded sockets into astraight line with the result that unbalanced shear forces are imposedupon the thread flanks, and the total moment of resistance of the pipesection is considerably reduced thereby.

- The above methods are also open to objection that they are expensiveand moreover the maintenance of the socket dimensions is dependent uponthe degree of diligence and dexterityoi the operator.

The object of my invention is to eliminate the above objections toexisting methods of and machines for machining and threading sockets andthe like.'

According to my invention a socket or like blank is initially set up ina machine, thenecessary machining operations are effected on one end ofthe blank and then, without disturbing the setting of the blank, theother end thereof is treated in a like manner.

According to a further feature of the invention a pair of sockets orlike blanks are initially set up in a machine and whilst one end of oneblank receives the necessary machining operation, one end of the otherand previously machined blank is simultaneously screw threaded.

The invention also consists in a machine for machining sockets, pipesand the like and/or for screw threading the same wherein a reversiblechuck is provided whereby after a socket has been initially set up inthe chuck both ends of the socket can be machined without disturbingthis setting.

The invention alsoconsists in a machine for machining and screwthreading sockets, pipes and the like wherein a pair of chucks areprovided in combination with two machining heads and a screw threadinghead all of which heads are movable to occupy positions relatively tothe chucks such that while one end of one socket or the like is beingmachined by one of the said machining heads the end of the other socketor the like which was previously machined by the other machining head issimultaneously threaded by the screw threading head.

The invention also comprises the further features hereinafter describedor indicated.

The invention will now be described with reference to the accompanyingdrawings which show, by way of example, an embodiment of the invention.

Figure 1 is a half longitudinal section of a boring tube socket;

Figure 2 is a front view of the machine;

Figure 3 is a front view of the machine partly in section and showingdiagrammatically the hydraulic connections to different parts of themachine;

Figure 4 is an end view of the machine with one of the pre-machiningheads in section and in the raised position;

Figure 5 is a similar view but with the premachining head in the loweredposition;

Figures 6, 'I and 8 are side and end views of the pre-machining toolpost;

Figure 9 is a side view of a valve controlling the vertical movements ofthe pre-machining heads;

Figure 10 is a section on the line Ill-40 of Figure 9; a

Figures 11, 12 and 13 are sectional views of a modified form of suchvalve;

Figure 14 is a diagrammatic view of the mechanical drives for the faceplates and for the tap head;

Figure 15 is an end view of the machine with the tap head in section;

Figures 16 and 17 are plan and part sectional side views respectively ofthe chuck, and

Figure 18 is a diagrammatic representation of the production schedule.

Referring now to Figure 1, this shows a half section of a pipe socketwhich it is desired to produce in large quantities. It will beunderstood that the socket must be faced at each end at I and must bethreaded internally with tapered threads 2, the outer end of eachthreaded portion being recessed at 3 and the exterior of each end of thesocket being chamfered as at I.

For carrying out these operations it is convenient to divide thefabricating operations into two main groups, namely. (1) pre-machiningand (2) threading. By pre-machining is meant all operations excepttapping (or screw threading) and these machining operations are,

(a) Facing of socket to length.

(b) Boring taper.

(c) Recessing end.

(d) Chamfering thread start.

(e) Chamfering outside.

These pro-machining operations are followed by a threading or tappingoperation which is preferably performed by means of a receding chasercollapsible tap of known kind, but which may be performed by any othersuitable appliance, for example a thread milling attachment.

It will be understood that the operations above described must becarried out on each end of the socket, and the double tapered threadmust be continuous from one end of the socket to the other, that is tosay there must be no step between the threads at the junction of thesetwo threads in the interior of the socket.

for the face plates 6 and I. operation of these movements will be morefully GENERAL ARRANGEMENT or MACHINE Referring now to Figure 2 themachine comprises a base 5 on which are mounted two rotatable faceplates 6, 1 carried by vertical spindies much on the lines of a verticaltwin spindle boring mill. Upon each face plate there is mounted a chuck8, 9'respectively adapted to hold the sockets. The rear of the base hasa rear column support It upon which is mounted a cross beam H whichcarries three tool posts generally designated by the references l2, l3and I4 which are arranged to move independently of one another and arein the following sequence; a premachining head It, a tap head l3 and asecond premachining head Id.

The invention is not limited to the use of vertically arranged spindlesand tool posts, since these for smaller units, particularly, may behorizontally disposed." In the case of pipe screwing machines it is ofcourse necessary that the spindles be arranged horizontally. The toolposts l2, l3 and M are moved along the cross beam by hydraulic means,including the cylinders I5, I 6 and I! respectively, the control ofthese movements being described hereafter. The upward and downwardmovement of the pre-machining heads l2 and H is also hydraulicallycontrolled, whilst the upward and downward movement of the tap head I3is controlled mechanically by a drive which is taken from the drive Thecontrol and described hereafter.

The sequence of operations to be carried out by the machine will now bedescribed, and the means for effecting these movements will then bedescribed in greater detail.

In operation a socket blank for the production of a socket, as shown inFigure, 1, is secured in one of the chucks, for example chuck 8, and thepro-machining head I2 is brought over this chuck and the operations (a)to (e) inclusive, above enumerated, are performed on one end of thesocket. The pre-machining head I2 is then moved along the cross beam IIto the left (Figure 2) and the tap head I3 is brought over the machinedend of the socket in the chuck 8. This is the position shown in Figure2. During the threading operation the operator secures a second socketblank in the chuck 9 and the premachining operations on this blank areperformed by the second pre-machining head M.

The screw-tapping operation is generally of longer duration than thepre-machining operation, so that the operator is given suflicient timein which to set up and machine this second socket blank whilst threadingof the first blank proceeds. Upon completion of the pre-machining of oneend of the second socket in chuck 9 the machining head It is moved awayfrom this socket to the right (Figure 2) and replaced by the tap head l3which then operates to screw thread this end of the second socket. Theoperator reverses the chuck 8 holding the first socket and repeats themachining operations upon the other end of ,this socket whilst thetapping of the second socket proceeds. Production then proceeds in anuninterrupted manner by repetition of the sequence of operations abovedescribed by adjustment of the nuts 200, M0 respectively.

The hydraulic control of the movements of the pre-machining heads andthe tap head will now be described.

HYDRAULIC Cmcun's (a) Pre-machining heads Referring now to Figures 3, 4and 5, the premachining heads l2 and i4 are slidably mounted on thecross beam Ii and carry at their upper extremity the cylinders I5, IIrespectively. These cylinders l5, I! are arranged to move with respectto fixed pistons 18, i9 carried by piston rods 20, 2| respectively. Theouter extremities of these piston rods are secured to the cross beam itor to extensions thereof and are longitudinally adjustable for thepurpose hereinafter described. Each of the pistons i8, i9 is providedwith differential pistons on each of its operative faces. These pistonsare referenced i8a, l8b and lSa, itb and their purpose also will behereinafter described.

Pressure fluid is supplied from any suitable source, for example the oiltank 22 (Figure 4) and pump 23, to the flow line 24, and this line iscoupled to a port 25 (Figure 3) of a manually operable valve 26 securedto the machining head i2. A similar valve 21 is provided on themachining head l4 and has a port 28-simiiarly supplied from the flowline 24. The valve 26 is in the form'of a piston valve having a doublepiston 29,

38 which controls ports 25, 3|, 32, 33 and 34. The ports 3| and 32 areconnected to the return line 35 for the pressure fluid, whilst the port33 is connected by a pipe 333 to a port 36 at the right hand end (Figure3) of the cylinder IS. The port 34 is in like manner coupled to a port31 at the,

- the valve and from thence it flows through port 38 to the left handend of the cylinder IS. The pressure acting on the left hand end of thecylinder i 5 causes the pre-machining head to move to the left towardsthe position shown in Figure 3. During this movement the fluid containedbetween the right hand end of the cylinder i5 and the adjacent side ofthe piston is forced through the port 36, the connecting pipe 333, theport 33, the interior of the valve 26 and the port 32 to the return line35. Towards the end of the movement of the pre-machining head l2 to theleft the differential pistoni8b engages within its correspondingdiiferential cylinder i8c provided at the right hand end of the maincylinder i5. Fluid is thereby trapped within this differential cylinderbut is permitted to leak through a controllable by-pass valve 38 into anannular chamber formed between the main piston l8 and the differentialcylinder i8c, into which chamber the port 36 opens. The fluid by-passedthrough the valve 38 is therefore returned with the main flow of fluidto the return line 35. The by-pass valve 38 may be pre-set so as to givea determined amount of cushioning effect when the pre-machining head i2is moved to the left away from the chuck 8 into'its inoperativeposition.

When it is desired to move the pre-machining head i2 into its operativeposition over the chuck 8 the valve 26 is manually operated by means ofthe handle 39 so as to move the double piston 29, 30 into its otherextreme position. In this position pressure fluid enters the valvethrough port 25 as before and passes out through port 33 via the pipeconnection 333 to port 36 on the cylinder l5 At the same time the port3| is opened to the return line 35 and fluid can therefore fiow from theleft hand side of the piston I8 through the port 31, the connecting pipe333, the port 34 and the port 3| to the return line.

The pre-machining head l2 will thereupon be moved to the right (Figure3) with a relatively fast motion. Towards the end of this motion thedifferential piston l8a will engage the differential cylinder l8d at theleft hand end of the main cylinder 15 and the fluid trapped therein isby-, passed through a valve 40 to the main cylinder 15 by means of theby-pass connection 41. The bypass valve 40 may be controlled, as forexample by means of a needle valve 42, since this terminal slow motionof the pre-machining head I2 is utilized to effect one of thepre-machining operations above mentioned, namely the facing of thesocket to length. The pre-rnachining head is finally held in itsoperative position over the chuck 8 by the continued pressure upon theright hand end of the cylinder l5 and when the boss 300, integral withslide i2, abuts against adjustable screws 45 carried in an abutmentblock 233 secured to the cross beam ll.

As soon as the facing operation has been performed the pre-machininghead reaches the limit of its travel to the right (Figure 3) In thisposition a valve 43 carried in the boss 300 of the premachining slide isopened by its stem 44 coming into contact with the stop 45 carried bythe cross beam H. In this condition pressure fluid is conducted througha port 46 (which is incidentally used for the by-pass 38) to the inletport 41 'of the valve 43. In the open position of the valve 43 fluidpasses through the valve and out through a port 48 to initiate thevertical movement of the pre-machining head. The fluid control of thevertical movement of the pre-machining heads will be hereinafterdescribed. The purpose of the axial adjustment of the piston rods 28, 2|is to determine at which position, during the travel of thepre-machining head, the facing operation commences in order to allow forthe facing of sockets of different diameters. Thus this adjustmentenables the facing period to be limited to that necessary for theparticular socket being faced.

' The boring position of the pre-machining head to give the set diameterdimension is fixed by the stop 45 contact of the boss 300 of the valve43 with which performs the dual function of firstly limiting the travelof the pre-machining head and secondly operating the valve 43.

(b) Tap head The tap head I3 is moved along the cross beam II byhydraulic means similar in all respects to that provided for thepre-machining heads. The-cylinder l6 carried by the tap head l3cooperates with a piston 49 having differential pistons 49a and 49b,pressure being admitted to either side of the piston by means of a valve50 similar to the valve 26. The cylinder in each of its end positions isadapted to contact with adjustable stops 5|, 52 so that its positioningdirectly over the chuck 8 or 9 can be accurately determined. The taphead I3 is maintained in each of its two end operative positions byfluid pressure and its movements towards and away from these endpositions is effected rapidly with a short terminal slow movementproduced by the action of the differential pistons 49a, 49b within theirrespective differential cylinders which are provided with controllableby-passes 53, 54. The vertical movenients of the tap head are producedby mechanical means associated with the drive for the chucks 8 and 9,and these means will also be hereinafter described.

Drrmrps or FEE-MACHINING I'IEAD AND TooL los'r It will be convenient nowto refer to Figures 6, 7 and 8 which show details of the tool post. Thetool post comprises a shank 55 which is secured to the moving portion 56(Figure 4) of the pre-machining head I2 and which is inclined so as tobe parallel with the taper to be bored in the socket. The shank 55 hasan extension 51 which serves to carry the tools 58 and 59. The tool 58is adapted to face the socket to length and to produce the tapered bore.The tool 59, which is disposed at right angles to the tool 58, as willbe clear from Figures 6 and '7, effects the recessing operation at theend of the socket. Due to this angular separation of the tools 58 and 59the former will produce the desired tapered bore whilst the latter willproduce an exact cylindrical access within the limits of accuracydemanded. A further tool 60 is carried by a tool holder 6| secured to aplate 62 through which the extension 51 passes. The plate 62 may besecured to the shank 55, as for example by welding as at 63. The tool 60effects the external chamfering of the end of the socket at thecompletion of the boring operation, as illustrated in Figure 6.

Referring now more particularly to Figures 4 and 5, the pre-machininghead I2 is adapted to house a slidable portion 56 movable in guides 64,65 (Figure 2) and the movement slightly inclined to the vertical axis ofthis portion is hydraulically controlled as above mentioned. Theslidable portion 56 is formed internally as a cylinder 66 with whichco-operates a stationary piston 61. The piston 61 has a piston rod 68secured to a bell housing 69 which in turn is carried by a fixed housing10 secured to the transverse sliding head I2. is provided with a bore Hthroughout its entire length, and with a further bore 12 opening at thefree end of the piston rod at one end, and opening into the cylinder 66above the piston 61 at its other end. The piston 61 is also providedwith a differential piston 13 co-operating with a differential cylinderI4 which forms an extension of the main cylinder 66. The pipe ll opensthrough the face of the differential piston 13 and also into the maincylinder 66 through a duct 15. Between the differential piston 13 andthe main piston 61 there is provided an annular enlargement 16 whichcomes into contact with the end of the cylinder 66 when the verticallymoving portion 56 is in its uppermost position. In this position (Figure4) the differential cylinder I4 is in communication through the bores Hand 15 with the portion of the main-cylinder 66 between the piston 61and the end of this cylinder.

Pressure fluid is delivered from the flow line 24 to the-bore 12 so thatit is constantly delivered to the cylinder 66 above the piston 61. rThis has the effect of returning the sliding portion 56 to its uppermostposition whenever pressure is released from the under-side of the piston61. This is the case whenever the pre-machining head is out of contactwith the stop 45 (Figure 3).

When the pre-machining head is caused to move towards this stop the tool58 during the The piston rod 68 final slow motion of the rare-machininghead faces the socket blank to length. Immediately after the facingoperation has been completed the stem 44 of the valve 43 is depressed bycoming into contact with the stop 45 (Figure 3). The movement ofthevalve 43 allows pressure fluid to pass through the valve and to enterthe port 11 of the valve 18 (Figures 4, 9 and 10). The valve 18comprises a body secured to the housing 10 and a hollow plunger 19provided with annular grooves Hand 8!. The annular groove 8| in theposition of the valve shown in Figure 9 cooperates with a port 82 whichcommunicates with an outlet 83 which is connected to the bore H in thepiston 61. The outlet 83 also communicateswith a port 84 with which theannular groove is adapted to co-operate. A further port 85 is alsoprovided which is connected to the return line 35 (Figure 4).

Within the hollow plunger'19 there is provided an operating rod 86 thelower end of which is secured to an extension of the slidable portion 56of the pre-machining head (Figure 4). The upper portion of the hollowplunger 19 has a larger internal diameter tofhousea spring 81 the lowerend of which bears against the plunger whilst the upperend bears againstan adjustable sleeve 88 which is locked in position on the operating rod86'ioy means of a nut 89.

At the upper end of the valve 18 there is provided an operating handle96 pivotal upon the body of the valve and having a pair of side arms 90,9| provided with recesses within which can slide a rod 92 which is urgedaway from the pivot pin 93 by springs 94, 95. The central portion of therod 92 is held in a bearing 92!) formed at the upper end of plunger 19.The compression springs 94, retain the handle 96 in the position shownin Figure 9, that is in the position prior to the commencement of theboring operation. As soon as presseur fluid is delivered to thepre-machining head through the valve 18 the vertically moving portion 56commences to descend and carries with it the operating rod 86.

During the downward movement, spring 81 is compressed by the resistanceoffered by springs 94, 95, which resistance increases until theoperating handle takes up a horizontal position. Just a little below thehorizontal position of the handle the compression energy of springs 81,94 and 95 is released, urging the hollow plunger 19 downwards, towardsits lower operative position. The supply of pressure fluid to the lowerface of the piston 61 is thereupon terminated and the bore II isconnected to exhaust through the annular groove 80 and port 85. Thevertically moving portion 56 thereupon commences to ascend under theconstant pressure supplied to the cylinder 66, the operating rod 86being returned at the same time to its initial position. Thepre-machining operations having been completed the operator will thenmanually operate the valve 26 to move the pre-machlning head away fromthe socket blank and the valve 43 will thereupon close. In order tobring the hollow plunger back into its initial operative position theoperating handle 96 (Figure 9) is manually moved to the position shownin Figure 9. The pre-machining head is then ready for the next cycle ofpre-machining operations. It will be clear that the extent of verticalmovement of the pre-machining head can be predetermined by adjustment ofthe sleeve 88 and associated lock nut 89 on the operating rod 86.

The above described form of valve is mechanicaily operated in onedirection and manually in the other direction, but, if desired, thevalve may be made fully automatic, that is to say upon the completion ofthe tire-machining operations the tool post may be withdrawn from thesocket and the valve controlling the vertical movements may be returnedautomatically to its initial position ready for the next cycle ofpre-machining operations. A suitable form of automatic valve is showninj'igures 11, 12 and 13. In these figures the operating rod 86 issecured to an extension of the vertically moving portion 56 of thepremachining headand is arranged to pass freely through a cross head 91which is adapted to be engaged in one end position by a shoulder on theportion 50 as shown in Figure 11. The cross head 91 has secured to it,with a certain amount of free play, a valve member 98 which over aportion of its length is adapted to obturate within a body 09 secured toa fixed portion of the pre-machining head. The remainder of the valvemember 98 is of reduced diameter and is adapted to slide within a sleeveI which itself is capable of sliding movement in the body 99. In thisbody 99 there are provided two annular ports IM and I02, the formerbeing connected to the return line 35 and the latter being connected tothe valve 43 and to the bore II of the pre-machining head (Figure 4).The valve member 08 is provided with an internal bore I03 whichcommunicates with two sets of openings I04, I which are so spaced apartas to connect the annular ports I III, 102 together through the bore mewhen the valve member 98 is in the appropriate position. The sleeve I00is also provided with a ring of ports I06 which are spaced from the endof this member by a distance which corresponds to the distance betweenthe ports IM and H02.

In the position of the parts shown in Figure 11 the pre-machining headis in its extreme return position, that is to say it is in the positionbefore the commencement of the pro-machining operations. When pressureis admitted to the annular ports I02 through the inlet duct N1 thepremachining head will descend, carrying with it the operating rod 86and disengaging the shoulder on the sliding part 56 from the cross head91. The downward motion continues until the cross head 91 is moved tothe right (Figure 11) by engagement of the nuts I08 carried by theoperating rod 86 with the cross head. The initial movement takes up the.lost motion and the further movement causes the valve member 98 and thesleeve I00 to be moved to the right into the position shown in Figure 12where the ports I06 of the sleeve register with the exhaust ports IOI,the inlet ports I02 being practically entirely covered by the largerportion of the valve member 98. In this position of the ports pressurefluid is permitted to escape from the ports I02 through suitableapertures between the end of the sleeve I00 and the larger portion ofthe valve member 98 into the bore I03 of the said member. This pressureacting on the valve member 98 and upon the sleeve causes the rapidseparation of these members which is permitted by the lost motionprovided between the valve member 98 and the cross head 91 so that theparts assume the relative positions shown in Figure 13. In this positionthe exhaust ports and inlet ports are in direct communication with oneanother through the bore I03 and the space beneath the piston 81 isplaced to exhaust through the bore II, duct I01, etc. The verticallymoving portion I8 thereupon moves upwards and the operating rod I8 ismoved towards its initial operative position. Towards the end of thisreturn motion of the pre-machining head the cross head 91 is engaged bythe before-mentioned shoulder and is carried back into the initialposition, the parts then assuming once more the relative positions shownin Figure 11, and the valve is reset for the next cycle of pre-machiningoperations.

It will be understood, of course, that whilst the above description hasbeen concerned solely with one of the pre-machinlng heads, exactly thesame arrangements are adopted for the other pre-machining head which iscontrolled in a like manner.

Face: PLATE Dawns The drives for the face plates 6 and I are showndiagrammatically in Figure 14 and are obtained from a prime mover suchas an electric motor I08. The said prime mover may be coupled to theface plates through the intermediary of a variable speed gear box I I0which is desirable in order to obtain the necessary speed variations ofthe face plates required for the machining and screw threadingoperations.

The variable speed gear box I Ill has two driven shafts III, M2, whichare each coupled through suitable gearing to the associated chuckspindles H3, H0. The drives from each shaft to each spindle areidentical, and therefore only one will be described, but it is to beunderstood that the same parts are provided for each spindle.

The driven shaft III of the variable speed gear box IIO has mounted uponit a gear wheel M5 which engages with a further gear wheel ME whichforms one of a pair of speed reducing idler wheels, the other, I", ofwhich meshes with a gear wheel II8 loosely mounted upon the spindle H3.The driven shaft III also carries freely mounted upon it a further gearwheel I I9 which is adapted to drive through an idler I20 a gear wheelI2I secured to the spindle I I3. The gear wheel IIO carries one portionof a clutch the other portion of which is slidably but not rotatablymounted upon the shaft III and is operated. by a suitable operatinghandle (not shown). The gear wheel II8 loosely mounted on the spindleII3 has a single claw projection I 22 which is adapted to be engaged bya similar claw projection I23 provided on a clutch member I24 slidablybut non-rotatably mounted upon the chuck spindle H3 and controlled by asuitable handle (not shown). When the clutch member I24 is disengagedfrom the single claw projection I22 the spindle H3 and associated faceplate 8 may be driven by engagement of the clutch carried by the drivenshaft III. This latter drive comprising the gear wheels 0, I20 and I2!is the fast drive for the table which is employed for the pre-machiningoperations where a cutting speed of 150 feet per minute (for example) isdesirable. When this drive is disengaged and the clutch carried by thespindle II 3 is engaged the face plate speed is reduced, for example, to12 feet per minute, which is a suitable screwing speed. v

- The spur wheel II8 loosely rotating on spindle I I3 is permanentlyconnected to a further gear wheel I25 which is adapted to rotate a shaftI28 (shown diagrammatically in Figure 14) which conveys a drive to thetap head lead screw, and this drive will be hereinafter described moreparticularly with reference to Figure 15.

TAP HEAD DivrAILs Referring now particularly to Figures '14- and 15, thetap head I3 comprises a slide I21 adapted to be moved along the crossbeam II, and a housing I28 secured to the slide I21 which, in turn,carries the vertically moving portion I 29. This latter portion I29 hassecured within it a lead screw nut I30 co-operating with the lead screwI3I which is carried in bearings at its upper end in the slide I28. Thelead screw I3I is adapted to be driven through two trains of gears thefirst of which comprises a gear wheel I32 loosely mounted upon the leadscrew and provided with dog clutch serrations adapted to engage similarserrations on the dog clutch I33 which is slidably but non-rotatablymounted upon the lead screw I3I. The gear wheel I32 meshes with an idlerI320 which in turn meshes with a further gear wheel I330. secured on thevertical shaft I34 carried in bearings at its upper and lowerextremities in the slide I28. The other train of gears comprises a gearwheel I35 rotatably mounted on the lead screw I3I and adapted to besecured thereto by a single dog clutch serration I36a which engages aco-operating serration on the clutch portion I33. The gear wheel I35meshes with a small gear wheel I36 which is coupled to the gear wheelI31 which meshes with a further gear wheel I38 carried on the verticalshaft I34. The gear train comprising the gear wheels I35, I36, I31 andI38 isa speed reducing train for giving the slow downward movement ofthe vertically moving portion I29. The vertical spindle I34 carries afurther skew gear wheel I39 which is driven by a further skew gear wheelI40 slidably but non-rotatably mounted upon a shaft I carried in.bearings I42, I43 (Figure 2) in the belly of the cross beam II. Thisshaft I4I receives its rotation from a further shaft I44 through themedium of a pair of gear wheels diagrammatically shown at I45 (Figure2), the shaft I44 being carried in bearings in the cross beam II. Theshaft I 44 in turn receives its drive from the shaft I26 (Figure 14)through the medium of a pair of bevel wheels I46, I41. The shaft I26(Figure 15) is split and provided with an adjustable coupling I48 whichcomprises two parts each of which is secured to one portion of the shaftI26 so that the upper portion of the shaft I26 may be adjusted angularlyin relation to the lower portion of the shaft I26 and locked in thisangularly adjusted position. The purpose for which this coupling I48 isprovided will be hereinafter described. It will be clear that the shaftI26 receives a continuous rotation from the variable speed gear box II0, and this rotation is conveyed to the lead screw through the clutchI33. In the upper position of this clutch (Figure 15) the lead screw isrotated slowly so as to move the portion I29 of the tap head downwardsto effect the tapping operation. When the clutch is in its lowerposition the gear train comprising the wheels I32 and I33 is broughtinto operation, the other train running freely, and the lead screw isgiven a faster rotation in the reverse direction to withdraw the portionI 29 and, consequently, the tapping tool from the socket. The tappingtool I49 is of any convenient kind and may, for example," be a recedingchaser collapsible tap the cutting elements of which are non-rotatablebut are receded as the tap proceeds into the socket so that the taperedbore of the socket may receive a tapered thread.

The clutch I33 may be mechanically operated so that when the tap reachesits lowest position the c ch is disengaged from the tapping drive.Thisfl'majconveniently be accomplished by providingthe clutch I33 with astriker bar I50 which is engaged by a tappet I5I adjustably secured on arod I52 carried by the vertically moving portion I29 of the tap head.The fast upward drive for the tap head may also be disengaged by ar--ranging a further tappet I53 on the rod I52 so that when the verticallymoving portion I29 nears the top of its travel the tappet I53 willengage the striker bar I50 and disengage the clutch I33. As shown inFigure 2 the striker bar I50 is preferably also mechanically coupled toa manually operable handle I54 so that the clutch may be positivelyengaged by hand to start the tapping operation.

Further, means may be provided to counteract chatter of the lead screwI3I in the lead screw nut I30, and these means may comprise an auxiliarynut I55 carried by the lead screw BI and a housing I56 secured to theportion I29, a spring I61 being interposed between the nut I55 and thehousing I56 so as to maintain one face of the threads of the lead screwI3I constantly pressed against one face of the threads of the lead screwnut I30.

REVERSIBLE CHUCK Referring now to Figures 16 and 1'1, the reversiblechuck 8 or 9 (Figure 2) comprises a body portion I58 which issubstantially in the form of a cylinder closed at one end. Within thisbody I58 there is mounted a substantially rectangular frame I59 whichhas trunnions I60 engaging in the walls of the body I58 so that theframe I59 may be rotated with respect to the body. The trunnions I60 arehollow and are provided internally with nuts I6I which'are engaged bythreaded bolts I62 carrying chuck jaws I63 which are adapted to grip thesocket blank. In order to secure the frame I59 against rotation, wedgeblocks I64 are provided which are adapted to be inserted beneath theframe I59 by the engagement of bolts I65 with threaded apertures in thewedges I64. The bolts I65 may be provided with pinions I66 which are inengagement with a circular rack I61 which can be manually rotated by acircular hand wheel I68. In order to secure a socket blank in the chuckthe threaded bolts I62 are operated to separate the chuck jaws I63- andthe socket is inserted so that its one end face rests upon an extensionof the wedges I64 as shown clearly in Figure 17. The chuck jaws are thentightened so as to grip the socket in a central position. Thepre-machining and tapping operations are then performed on the top halfof the socket and in order that the other end of the socket may betreated in a like manner the hand wheel I68 is manually rotated in theappropriate direction to cause withdrawal of the wedges I64 from theframe I59. As soon as the wedges have been withdrawn sufficiently farthe frame carrying the partly machined socket may be rotated in itstrunnions so that the socket is reversed end for end. The hand wheel I68is then again operated in order to replace the wedges beneath the frameI59. The further machining and tapping operations may then be performed.

TAP Hmn DRIVE SETTING r01: CONTINUITY or THREAD As has been previouslystated it is a requirement for boring tube sockets that the internalthread should continuous from one end of the socket to the other,although the complete thread has a double taper, its smallest diamet rbeing at the middle of the socket as is clearly shown in Figure 1.

In view of the fact that each socket is machined and tapped at one endbefore the other end has been machined it is necessary that means heprovided to ensure that when the socket is reversed for the secondthreading operation to be performed the tapping operation will bestarted at the correct point on the circumference of the machined blankso that the second thread will accurately run into the first thread atthe middle of the socket. The actual setting operations will now bedescribed so that the operation of the means previously referredto forensuring continuity of thread will be clearly understood.

Referring now to Figure 2, let it be assumed that a socket blank hasbeen inserted in the chuck 8 and that the pie-machining operations havebeen completed on one end only of this socket. The pre-machining head I2is then moved to the left and the tap head I3 brought over the socketblank. The coupling I48 (Figure 15) is then disconnected and the tappingtool is brought down by hand rotation of the upper portion of the shaftI26, the clutch I33 being engaged with the clutch portion on the gearwheel i35 until the distance from the centre of the vice body (and thusfrom the centre of the socket) and a selected tooth of the tapping toolmeasures exactly a multiple of the'pitch of the thread to be cut. Thetwo parts of the coupling M8 are then secured together and the settingup operation is complete. The drive for the face plates is through asingle claw clutch I22, I23 (Figure 14) previously referred to andthrough the single claw clutch I33, I36 (Figure 15). Since the tappingtool has been set as above described the engagement of the drive for thedownward movement of the tap can only be made when the socket blank hasthe correct angular position relative to the tapping tool. By reason ofthis fact when the first thread has been cut in a blank and the blank isthen reversed end for end in the chuck above described it follows thatthe succeeding tapping operation 'on the other end of the blank will becarried out so that the second thread accurately meets the first threadso as to produce a continuous thread throughout the socket. It will beunderstood that when sockets having a different number of threads perinch have to be out then a similar setting up operation will have to beperformed, since the setting for ;one thread will not necessarily becorrect for another thread. It may also be mentioned that since thedrive for the face plates is taken from a common gear box and both faceplates are driven through single claw clutches the setting up operationperformed with respect to one face plate will be correct for the otherface plate also provided that the claw projection I22 of each of thegears H8 is initially set up with respect to the drive from the gear boxIII! so that each bears the same angular relationship to a selectedtooth of the tapping tool when the gear wheels I I8 are stationary.

SEQUENCE or OPERATIONS Referring now particularly to Figures 2 and 18 incommencing the mass production of boring tube sockets the first blank isset up in the chuck 8, the tap head I3 and the pre-machining head I4 aremoved to the right (Figure 2) and the prem'achining head I2 ishydraulically brought over the socket by operation of the handle 39. The

face plate 6 is given its high speed of rotation by engagement of theclutch associated with the gear wheel II9. This is effected by operationof the handle I69 (Figure 2) which is moved in one direction to engagethis clutch and in the other direction to engage the clutch I23. Thepremachlning operations are thereupon automatically carried out and theboring tools returned to their uppermost position. This first operationis shown in line A of Figure 18. The pre-machining head it is then movedto the left by further operation of the handle 39 and the tap head I3 isbrought over the blank and the above mentloned setting operationsperformed, having regard to the particular pitch of thread to be cut inthe socket. The tapping operation is then commenced by operation of thehandle 65% to engage the tap head clutch I33 with the slow speed train,and the tapping operation proceeds to completion when the tapping toolis withdrawn automatically from the socket. During this tappingoperation a further blank is set up in the chuck 9 and the pre-machininghead It is brought over this socket, and there-machining operations arecarried out while the tapping operation on the first blank proceeds.This stage of the operations is shown in line B of Figure 13. Uponcompletion of the tapping operation on the socket in chuck it and thepre-machining operation on the socket in chuck 9 the pre-machining headIt is hydraulically moved to the right by operation of the handle 39 andthe tap head it is moved over this socket. The socket in chuck d is thenreversed end for end and the pre-machining head I2 is brought over thissocket to effect the pre-machining operations on the other half of thesocket. At the same time the tapping operation on the first end of thesocket in chuck Q is proceeded with. This stage is shown in line C ofFigure 18.

Upon completion of the lire-machining and tapping operations thepre-machining head I2 is moved to the left and the tap head is alsomoved to the left over the socket in chuck 8. The socket in chuck 9 isreversed end for end and the premachining head I4 is brought over thissocket so that the pre-machining operations on the second end may becarried out whilst the tapping operation proceeds on the second end ofthe socket in chuck 8. This stage is shown in line D of Figure 18. Athird socket is then inserted in chuck 8 and the pre-machining operationcarried on while the tapping of the second end of the socket in chuck 9proceeds. This stage is shown in line E of Figure 18. The subsequentproduction of sockets is carried on by repetition of the above sequenceof operations, and it will be appreciated that the tapping tool isalmost continuously in use since the tapping operation occupies a longertime than the pre-machining operation.

It will be understood that the invention is not limited to the foregoingdetails of construction which may be variously modified to suit theparticular requirements and practical conditions which it is desired tofulfil, since, for example, the apparatus may be arranged so that themovements of the pre-machining and tap heads are horizontal instead ofvertical and also more than two pre-machining heads may be employed inassociation with one or more tap head.

Nor is the invention limited to the machining of sockets which have beenselected merely by way of example in order to describe one mode ofcarrying out the invention since the invention may be utilizedfor'machining other objects subject to suitable modification as to theutilization of same or all of the features above described.

Having now described my invention, what I claim as new and desire tosecure by Letters Patent is:-

1. A machine for fabricating a pipe socket or like blank comprising areversible chuck for the workpiece, a tool post, a guide for the toolpost inclined to the longitudinal axis of the socket, a pluralityof'tools so disposed upon the tool post as to effect a plurality ofmachining operations upon the workpiece and means for traversing thetool post along said guide so that the tools can machine the workpiecein one progressive movement, said tools including a cutting tool mountedupon the tool post in such a position that its cutting edge lies at oneend of a first diameter of said socket and so that its movementrelatively to the socket produces a taper bore and a second cutting toolmounted upon the tool post so that its cutting edge lies at the end of asecond diameter of the socket at right angles to the said first diameterso that this second tool produces a substantially cylindrical bore.

2. A machine for fabricating a pipe socket or jointing pipe of theinternally screwed type comprising means for holding the workpiece, atool post, a guide for the tool post inclined to the longitudinal axisof the socket, a plurality of tools so disposed upon the tool post as toeffect upon the workpiece the premachining operations of facing tolength, boring, recessing and chamfering thread start and chamferingoutside and means for traversing the tool post along said guide so thatthe tools can premachine the workpiece in one progressive movement, saidtools including a cutting tool mounted upon the tool post in such aposition that its cutting edge lies at one end of a first diameter ofsaid socket and so that its movement relatively to the socket produces ataper bore and a second cutting tool mounted upon the tool post so thatits cutting edge lies at the end of a second diameter of the socket atright angles to the said first diameter so that this second toolproduces a substantially cylindrical bore.

3. A machine for fabricating a pipe socket or like blank comprisingmeans for holding the blank, a tool post, a guide for the tool postinclined to the longitudinal axis of the socket, a plurality of toolsrigidly mounted upon the tool post and each arranged to perform adifferent machining operation upon the blank, and means for traversingthe tool post along said guide so that the different machiningoperations can be performed in one progressive movement, said toolsincluding a cutting tool mounted upon the tool post in such a positionthat its cutting edge lies at one end of a first diameter of said socketand so that its movement relatively to the socket produces ataper boreand a second cutting tool mounted upon the tool post so that its cuttingedge lies at the end of a second diameter of the socket at right anglesto the said first diameter so that this second tool produces asubstantially cylindrical bore.

4. A machine for fabricating pipe sockets of the internally screwed typecomprising two premachining heads, two reversible chucks and a screwthreading head, a plurality of tools carried upon each premachining headso as to perform the operations of facing a socket to length, boring,recessing and chamfering thread start and chamfering outside, and meansfor moving the said heads so that while one end of one socket is beingpremachined by one of the premachining heads the end of another socketwhich ,was, previously premachined by the other premachining head can besimultaneously threaded by the screw threading head.

5. A machine for fabricating pipe sockets of the internally screwed typecomprising two premachining heads, two reversible chucks and a screwthreading head, a plurality of tools carried upon each premachining headso as to perform the operations of facing a socket to length, boring,recessing and chamfering thread start and chamfering outside, means formoving the premachining heads and the screw threading head intopositions where two of the heads are positioned opposite the saidchucks, and means for moving the premachining heads and" the screwthreading head so that their respective operations are performed uponthe sockets in one progressive movement.

.6. A machine for fabricating a pipe socket or jointing pipe comprisinga tool post, a guide for the tool post inclined to the longitudinal axisof the socket, a plurality of tools carried upon the tool post so as toperform upon the workpiece the premachining operations of facing tolength, boring and recessing and chamfering thread start and chamferingoutside, a chuck for holding the workpiece and means for moving the toolpost first transversely with respect to the workpiece and thensubstantially axially thereof and along said guide so that thepremachining operations are performed in one progressive movement of thetool post, said tools including a cutting tool mounted upon the toolpost in such a position that its cutting edge lies at one end of a firstdiameter of said socket and so that its movement relatively to thesocket produces a taper bore and a second cutting tool mounted upon thetool post so that its cutting edge lies at the end of a second diameterof the socket at right angles to the said first diameter so that thissecond tool produces a substantially cylindrical bore.

'7. A machine for fabricating a pipe socket or jointing pipe of theinternally screwed type comprising a premachining head and a screwthreading head, a plurality of tools carried upon the premachining headso as to perform upon the workpiece the premachining operations offacing to length, boring and recessing and chamfering thread start andchamfering outside, means for moving the premachining head relatively tothe workpiece so that the tools thereon perform their respectiveoperations in one progressive movement, means for moving the screwthreading head relatively to the work so that the threading operation isperformed in one progressive tool movement, and driving means formaintaining rotation of the workpiece, the said driving means beinginterconnected with the means for moving the screw threading head.

8. A machine for fabricating a pipe socket or jointing pipe of theinternally screwed type comprising a premachining head and a screwthreading head, a plurality of tools carried upon the premachining headso as to perform upon the workpiece the premachining operations offacing to length, boring and recessing and chamfering thread start andchamfering outside, means for moving the premachining head firsttransversely of the workpiece and then substantially axially thereof sothat the tools upon the premachining head perform their respectiveoperations in one progressive movement, means for moving the screwthreading head relatively to the work so 2,117,718 that the threadingoperation is performed in one progressive tool movement, and drivingmeans for maintaining rotation of the workpiece, the said driving meansbeing interconnected with the means for moving the screw threading head.

9. A machine as claimed in Claim 8 wherein the transverse movement ofthe premachining head comprises a fast period followedby a slow period.

' 10. A machine for fabricating a pipe socket or jointing pipe of theinternally screwed type comprising a premachining head and a screwthreading head, a plurality of tools carried upon thread start andchamfering outside, means for moving the premachining head transverselyof the workpiece so that the transverse movement comprises a fast periodfollowed by a slow period and, at the termination of the transversemovement, for moving the premachining head substantially axially of theworkpiece so that the tools upon the workpiece perform their respectiveoperations upon the workpiece in one progressive movement, means foradjusting the slow transverse movement of the premachining head, meansfor moving the screw threading head relatively to the work so that thethreading operation is performed in one progressive tool movement, and

driving means for maintaining'rotation of the workpiece, the saiddriving means being interconnected with the means for moving the screwthreading head.

11. A machine for fabricating a socket with a cylindrical bore followedby a tapered bore comprising in combination a chuck for holding thesocket, means for rotating said chuck, a tool post. a guide for the toolpost inclined to the longitudinal axis of the socket, means fortraversing the tool post along the guide, a cutting tool mounted uponthe tool post in such a position that its cutting edge lies at one endof a first diameter of said socket and so that its movement relativelyto the socket produces a taper bore and a second cutting tool mountedupon the tool post so that its cutting edge lies at the end of a seconddiameter of the socket at right angles to said RUDOLF FRANCIS WEISER.

